PROJECT SUMMARY AND ABSTRACT Background: Food allergy (FA) is a potentially life-threatening condition that affects an estimated 8% of children in the United States. Among food-allergic children, 25% have a peanut allergy (PA), one of the leading causes of fatal food-allergic reactions. In 2017, the NIAID published the Addendum Guidelines for the Prevention of Peanut Allergy in the United States [?Prevention of Peanut Allergy (PPA) Guidelines?], recommending dietary introduction of peanut products during infancy. The new PPA Guidelines present the following immediate clinical challenges for pediatricians: (a) to assess each infant's PA risk, (b) to test or refer high-risk infants to allergists; and (c) to counsel parents regarding how and when to incorporate peanut- containing products into an infant's diet. While the provision of PPA Guideline-consistent care has the potential to prevent PA, research has shown that dissemination and implementation of the PPA Guidelines has been inadequate, even though providers are knowledgeable about the guidelines and view them favorably. Specific Aims and Methods: The primary and secondary aims of this practice-based cluster- randomized controlled trial are to determine the effectiveness of an Intervention to Reduce Early (Peanut) Allergy in Children (iREACH) in increasing adherence to PPA Guideline practices among pediatricians and subsequently decreasing the incidence of peanut allergy in children. iREACH, incorporates a PPA Guideline education module, an EHR-integrated CDS tool at 4- and 6- months, and follow-up prompts within the EHR inquiring about parental peanut introduction practices. Pediatrician adherence will be measured through EHR data extraction after the 6-month visit. Peanut allergy incidence will be measured through a combination of parent-report via survey and EHR data extraction. Other exploratory objectives include: 1) Describing allergist adherence to the PPA Guidelines via EHR extraction, 2) Reporting barriers/facilitators for PPA Guideline adherence among pediatricians, allergists and parents via surveys, and 3) Describing rates of parental adherence (peanut product introduction and feeding frequency) to the PPA Guidelines via survey. Hypotheses and Expected Results: Our primary study hypothesis is that compared with infants in the control arm infants at high and low/moderate risk in the iREACH intervention arm, will have higher rates of pediatrician adherence to the PPA Guidelines. Our secondary hypothesis is that when compared to high and low/moderate risk infants in the control arm, those in the iREACH intervention arm will have lower rates of peanut allergy. Significance and Effects on Other Research: This will be the first study to systematically examine and promote the implementation of the PPA Guidelines, which have the potential to dramatically reduce the incidence of PA and its associated morbidity in the US. If found to be effective, iREACH is designed for swift national dissemination and implementation via a variety of common EHR platforms.